Spiral head adjusting screw

ABSTRACT

A fastener element has a wrench engaging portion provided with wrench engaging surfaces having a helical configuration about the rotational axis of the fastener element.

United States Patent 1 Lagasse H lMarch 13, 1973 1 SPIRAL HEAD ADJUSTING SCREW [75] Inventor: Joseph Louis Lagasse, Montreal,

Quebec, Canada [73] Assignee: Northern Electric Company, Ltd.,

Montreal, Quebec, Canada [22] Filed: Dec. 18, 1970 [21] Appl. No.: 99,639

Related U.S. Application Data [63] Continuation of Ser. No. 790,023, Jan 9, 1969,

abandoned.

[52] U.S. Cl. ..85/9 R [51] Int. Cl ..Fl6b 23/00 [58] Field of Search .;...85/45, 9

[56] References Cited UNITED STATES PATENTS 1,734,184 3/1972 Stoler ..85/45 2,538,350 1/1951 Baule Grimm et al.

3,354,757 11/1967 3,482,481 12/1969 Newell et al ..85/45 FOREIGN PATENTS OR APPLICATIONS 74,218 3/1918 Austria ..85/45 Primary ExaminerEdward C Allen Attorney-Philip T. Erickson [57 ABSTRACT A fastener element has a wrench engaging portion provided with wrench engaging surfaces having a helical configuration about the rotational axis of the fastener element.

3 Claims, 1 Drawing Figure PATENTEUMARIW; I ,7 0,129

INVENTOR JOSEPH L. LAGASSE BYM WW ATTORNEYS SPIRAL HEAD ADJUSTING SCREW BACKGROUND OF THE INVENTION This is a continuation of application Ser. No. 790,023, filed Jan. 9, l969, and now abandoned.

This invention relates to fastener elements and particularly to fastener elements comprising a threaded shank portion and a wrench engaging head portion.

Such head portions frequently have a regular polygonal cross-sectional shape, typically hexagonal or square. A wrench used to adjust such fastener elements is applied to an opposite pair of sides on the head portion and is rotated about the rotational axis of the fastener element to adjust the fastener element. With a hexagon, it is necessary to rotate the fastener element through about 60 in order to be able to transfer the wrench from one pair of opposing sides to an adjacent pair of opposing sides. In circumstances in which the wrench cannot be swung through the necessary rotational angle, it becomes impossible to adjust the fastener element.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fastener element having a wrench engaging portion of such a design that it may be used in a confined location where the extent of the swing of a wrench for use with the fastener element is severely restricted.

The invention provides, in a fastener element having a wrench engaging portion and a rotational axis and provided with two parallel wrench engaging surfaces extending generally parallel to said axis, the improvement in which said surfaces have a helical configuration about the axis.

In a particular embodiment of the invention the wrench engaging portion has a periphery of regular polygonal form and is provided with a plurality of opposing pairs of wrench engaging surfaces, each of said surfaces extending in helical configuration. Preferably, the surfaces have a rotation about the rotational axis of the fastener element sufficient that a part of one surface is coplanar with a part of the adjacent surface.

By use of the present invention, it is possible to provide the wrench engaging portion of a fastener element with a comparatively small number of wrench engaging surfaces and yet be able to rotate the fastener element in confined spaces in which the wrench has only a small angular movement possibility.

BRIEF DESCRIPTION OF THE DRAWING The invention will now be described, by way of example, with reference to the accompanying drawing which is a perspective view of a bolt embodying the present invention and a wrench for use therewith.

DESCRIPTION OF PREFERRED EMBODIMENTS As can be seen from the drawing, a bolt 1 has a screw threaded shank portion 2 and a head portion 3. The head portion has a hexagonal periphery in any crosssection taken perpendicular to the rotational axis 4 of the fastener element 1. The head portion 3 has three pairs of opposite parallel wrench engaging surfaces, noted at 50 and 5b, 6a and 6b, and 7a and 7b. The surfaces extend generally parallel to the axis 4 but with a helical configuration about the axis.

In the example shown, the opposed pairs of surfaces are rotated through between their ends. With this amount of rotation, the free end of the surface 5a is substantially coplanar with the end of the surface 7b adjacent the shank portion 2.

In use of the fastener element shown in the drawing, a wrench 10 is located on the head 3 with the faces 11 and 12 of the wrench in engagement with, for example, opposing surfaces 50 and 5b. The wrench is then moved about the axis 4 in the space available to the wrench, e.g. 5 to 15. When the rotational movement of the wrench is halted by an obstruction, it is moved axially of the axis 4 with the wrench faces 11 and 12 maintaining engagement with the surfaces 5a and 5b. The wrench returns to its original rotational position since it cams on the surfaces 5a and 5b during its axial movement. This is a new starting point from which the wrench is rotated for another 5 to 15 for example. This procedure is repeated until the wrench reaches one end of the helical surfaces 5a and 5b. At this time it is pulled off the head and returned to the other end of the head on a pair of adjacent surfaces, for example 7a and 7b. The operation is then repeated until such time as the fastener element is in its required position or is sufficiently tight in the assembly to which it is connected. It will be seen that the direction of rotation and axial movement of the wrench determine the direction of rotation of the fastener element during use thereof.

Although the invention has been described with reference to a bolt having a head provided with an external hexagonal cross-section, it will be understood that the principle of the invention can be applied to a nut and that the wrench engaging portion can have a square or other periphery providing two parallel surfaces of helical configuration.

Any of the normal methods of manufacture could be used to make the fastener element of the invention. For example, a bolt could be formed by taking a hexagonal bar, gripping the ends thereof and relatively twisting the ends so as to provide the helical configuration and finally machining the threaded shank. Alternatively, thehead could be cold-formed using dies of suitable configuration to provide the helical hexagonal configuration shown in the drawing.

I claim:

1. A rotary fastener element having a rotational axis, a threaded portion, and at least two pairs of diametrically opposed external parallel wrench-engaging surfaces extending generally parallel to said rotational axis over substantially the entire length of the longitudinal unthreaded portion of said fastener element to form the sole wrench-engageable surfaces of said fastener element, each transverse portion of said surfaces defining at least a portion of a cord of a circle having its center coincident with said axis, each said transverse portion being intersected at right angles by a radius of said circle, said surfaces having a helical configuration about said rotational axis and having a rotation about said axis sufficient that a portion of each surface is generally coplanar with a portion of an adjacent surface, each surface meeting an adjacent surface at an edge, and the surfaces of each pair being spaced apart diametrically a predeten'nined amount for engagement by a wrench of predetermined size, whereby the wrench may engage a pair of surfaces by being moved onto the fastener elesurface extending about said axis in said helical configuration through 60, one end of one of said surfaces being generally coplanar with that part of an adjacent surface adjacent the other end of said one surface.

3. A rotary fastener element according to claim 2, wherein the element is a bolt, and said pairs of surfaces are on the head of the bolt and are immediately adjacent said threaded portion. 

1. A rotary fastener element having a rotational axis, a threaded portion, and at least two pairs of diametrically opposed external parallel wrench-engaging surfaces extending generally parallel to said rotational axis over substantially the entire length of the longitudinal unthreaded portion of said fastener element to form the sole wrench-engageable surfaces of said fastener element, each transverse portion of said surfaces defining at least a portion of a cord of a circle having its center coincident with said axis, each said transverse portion being intersected at right angles by a radius of said circle, said surfaces having a helical configuration about said rotational axis and having a rotation about said axis sufficient that a portion of each surface is generally coplanar with a portion of an adjacent surface, each surface meeting an adjacent surface at an edge, and the surfaces of each pair being spaced apart diametrically a predetermined amount for engagement by a wrench of predetermined size, whereby the wrench may engage a pair of surfaces by being moved onto the fastener element in a direction substantially at right angles to said rotational axis, the fastener element being then turned through a certain angle by the wrench, the wrench then being moved back and, at the same time, longitudinally of the fastener element, and the fastener element is then turned through a further angle with the wrench still in engagement with the same said pair of surfaces.
 1. A rotary fastener element having a rotational axis, a threaded portion, and at least two pairs of diametrically opposed external parallel wrench-engaging surfaces extending generally parallel to said rotational axis over substantially the entire length of the longitudinal unthreaded portion of said fastener element to form the sole wrench-engageable surfaces of said fastener element, each transverse portion of said surfaces defining at least a portion of a cord of a circle having its center coincident with said axis, each said transverse portion being intersected at right angles by a radius of said circle, said surfaces having a helical configuration about said rotational axis and having a rotation about said axis sufficient that a portion of each surface is generally coplanar with a portion of an adjacent surface, each surface meeting an adjacent surface at an edge, and the surfaces of each pair being spaced apart diametrically a predetermined amount for engagement by a wrench of predetermined size, whereby the wrench may engage a pair of surfaces by being moved onto the fastener element in a direction substantially at right angles to said rotational axis, the fastener element being then turned through a certain angle by the wrench, the wrench then being moved back and, at the same time, longitudinally of the fastener element, and the fastener element is then turned through a further angle with the wrench still in engagement with the same said pair of surfaces.
 2. A rotary fastener element according to claim 1, wherein the element has three pairs of surfaces, each surface extending about said axis in said helical configuration through 60*, one end of one of said surfaces being generally coplanar with that parT of an adjacent surface adjacent the other end of said one surface. 